Door for home appliance, home appliance, and method for manufacturing the same

ABSTRACT

A door for a home appliance, a home appliance, and a method for manufacturing the same, are disclosed. The door for a home appliance comprises a panel assembly; and a frame assembly defining a predetermined space having an opening connected with an edge of the panel assembly, and making a foaming space for receiving a thermal insulator by means of the predetermined space of the frame assembly and the edge of the panel assembly, wherein a foaming injection hole through which the thermal insulator is injected is provided on at least one of ends of an upper surface, a lower surface, a left side and a right side of the frame assembly.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Divisional Application of U.S. patent applicationSer. No. 16/685,631 filed Nov. 15, 2019, which is a ContinuationApplication of U.S. application Ser. No. 16/252,389, filed Jan. 18,2019, which is a Continuation application and claims priority to U.S.patent application Ser. No. 15/310,173, filed Nov. 10, 2016 (now U.S.Pat. No. 10,228,182), which is a U.S. National Stage Application fromPCT/KR2016/007764, filed Jul. 15, 2016, which claims priority fromKorean Application No. 10-2015-0100427 filed Jul. 15, 2015, the entirecontents of which are hereby incorporated by reference.

BACKGROUND 1. Field

Embodiments may relate to a door for a home appliance, a home appliance,and/or a method for manufacturing the same.

2. Background

A refrigerator is an apparatus for freeze or refrigerate foods bymaintaining a temperature of a storage area provided therein at apredetermined temperature by using a freezing cycle configured of acompressor, a condenser, an expansion valve and an evaporator.Therefore, the refrigerator includes a storage area, for example, afreezer compartment and a refrigerator compartment, and its type isclassified in accordance with positions of the freezer compartment andthe refrigerator compartment. For example, the refrigerator may beclassified into a top mount type having a freezer compartment mounted ona top of a refrigerator compartment, a bottom freezer type having afreezer compartment mounted below a refrigerator compartment, and a sideby side type having freezer and refrigerator compartments arranged sideby side.

The freezer compartment and the refrigerator compartment are providedinside a cabinet forming external appearance, and each of them mayselectively be opened and closed by a freezer door and a refrigeratordoor. Some refrigerators include a user input panel provided on a doorfront surface. The panel may be provided to allow a user to apply atouch input thereto. This may be referred to as an interactive touchinput panel. The user may select or change various functions of therefrigerator through the interactive touch input panel. Somerefrigerators, particularly, a show case refrigerator used in aconveniences store may allow a user to see the inside of therefrigerator even without opening a door because the door is comprisedof glass. However, since a refrigerator for home use includes an opaquefreezer door and an opaque refrigerator door, it is general that theuser may see the inside of the refrigerator by opening the freezer doorand the refrigerator door.

In some refrigerator for home use, a user may see the inside of therefrigerator even without opening a door of the refrigerator. Therefore,cool air loss caused by frequently opening or closing the door may beavoided.

In this refrigerator, the door may include a panel assembly throughwhich a user may see the inside of the refrigerator, and a frameassembly for supporting the panel assembly.

Meanwhile, the freezer compartment and the refrigerator compartment areprovided inside a cabinet constituting external appearance of therefrigerator, and selectively opened or closed by a freezing door and arefrigerator door (hereinafter, referred to as “door for refrigerator”or “door” as a generic term. Since the refrigerator compartment or thefreezer compartment are selectively sealed by the door for therefrigerator, the door should have predetermined insulation performance.To this end, a predetermined space is formed by a frame structure bodyconstituting external appearance of the door to have a predeterminedrigidity, the space is generally foamed and filled with a thermalinsulator such as polyurethane to make a door. Since the frame structurebody is a thin plate member, a foaming space determined by the framestructure body becomes a size of the door, that is, “upper and lowerwidth of the door x left add right width of the door x depth of the door(front and rear direction of the door)”, and this space becomes afoaming space and a foaming path, which should be filled with a thermalinsulator.

In this door, since a size of the door becomes a foaming space, and thefoaming space becomes a foaming path, the foaming path is relativelygreat. Therefore, a foaming injection hole is arranged at a center,approximately, of a rear surface (exactly, frame structure body) of thedoor. The temporary assembly door is arranged horizontally to allow thefront surface of the temporarily assembled door toward the groundsurface during foaming of the thermal insulator, and then the foamingagent which is the thermal insulator is injected through the foaminginjection hole provided at the center of the rear surface of thetemporary assembly door.

Meanwhile, since the aforementioned door for a refrigerator is opaque, auser may see the inside of the refrigerator by opening the freezer doorand the refrigerator door. Recently, a refrigerator for allowing a userto see the inside thereof even without opening a door thereof has beensuggested to reduce door opening or closing of thereof and thus avoidcool air loss caused by frequently opening or closing of the door.

In this refrigerator, the door may include a panel assembly comprised ofglass through which the user may see the inside of the refrigerator, anda frame assembly for supporting the panel assembly. Of course the doormay include a panel assembly having a touch input assembly and a frameassembly for supporting the panel assembly.

However, in the door for the refrigerator, the foaming space and thefoaming path becomes a space defined by a portion except the panelassembly from the entire door, that is, an outer edge of the frameassembly and the panel assembly. Therefore, the door has a relativelysmaller foaming space and foaming path than those of a general door, aproblem may occur during foaming of the thermal insulator. That is,since foaming resistance is great during foaming of the thermalinsulator, a problem may occur in that the foaming space may not befully filled with the thermal insulator. Also, the foaming agent typethermal insulator may be swollen to leak into the foaming injection holeor the panel assembly or the foaming agent may flow backward to thefoaming injection hole. Therefore, a solution for solving this problemis required.

This problem of the door may occur equally or similarly to a door of ahome appliance, which requires insulation, as well as a door of arefrigerator.

DISCLOSURE Technical Problem

Embodiments of the present invention is directed to a door for arefrigerator, a refrigerator and a method for manufacturing the same,which substantially obviate one or more problems due to limitations anddisadvantages of the related art. An object of the present invention isto provide a door for a refrigerator, a refrigerator and a method formanufacturing the same, in which foaming performance of a thermalinsulator can be improved during manufacture of the door.

Technical Solution

According to one embodiment of the present invention, a door for a homeappliance comprises a panel assembly; and a frame assembly defining apredetermined space having an opening connected with an edge of thepanel assembly, and making a foaming space for receiving a thermalinsulator by means of the predetermined space of the frame assembly andthe edge of the panel assembly, wherein a foaming injection hole throughwhich the thermal insulator is injected is provided on at least one ofends of an upper surface, a lower surface, a left side and a right sideof the frame assembly. The frame assembly includes a rear frame locatedon a rear surface of the door, and a side frame forming thepredetermined space connected with the rear frame. The panel assemblyincludes two or more thermal insulation glass panels and a spacerprovided between edges of the two thermal insulation glass panels, and aheating element is provided near the spacer.

Preferably, the frame assembly has a depth substantially the same asthat of the panel assembly. The frame assembly may have a width of 35 mmor less. Meanwhile, the foaming injection hole is preferably provided atboth ends of the frame assembly.

Meanwhile, the foaming injection hole is preferably provided on at leastone of the ends of the upper surface and the lower surface of the frameassembly. More preferably, the foaming injection hole is provided at theend of the lower surface of the frame assembly. More preferably, thefoaming injection hole is provided at both ends of the lower surface ofthe frame assembly. Meanwhile, the foaming injection hole is preferablyprovided in a long length direction of the frame assembly.

According to another aspect of the present invention, a door for arefrigerator comprises: a cabinet constituting appearance of therefrigerator; a main door rotatably coupled to the cabinet; and a subdoor rotatably coupled to the main door, wherein the sub door includes apanel assembly; and a frame assembly defining a predetermined spacehaving an opening connected with an edge of the panel assembly, andmaking a foaming space for receiving a thermal insulator by means of thepredetermined space of the frame assembly and the edge of the panelassembly, wherein a foaming injection hole through which the thermalinsulator is injected is provided on at least one of ends of an uppersurface, a lower surface, a left side and a right side of the frameassembly.

According to still another aspect of the present invention, a door for arefrigerator comprises a support portion surrounding an opened centerportion, having a thermal insulation space therein, and a thermalinsulator received in the thermal insulation space, wherein a foaminginjection hole through which the thermal insulator is injected isprovided on at least one of ends of an upper surface, a lower surface, aleft side and a right side of the support portion.

According to further still another aspect of the present invention, amethod for manufacturing a door for a refrigerator comprises a temporaryassembly step of temporarily assembling a support portion surrounding anopened center portion, having a thermal insulation space therein; and afoaming step of injecting the thermal insulator in a length direction ofthe support portion.

At the foaming step, it is preferable that the thermal insulator isinjected in a long length direction of the support portion. At thefoaming step, it is more preferable that the thermal insulator is foamedafter the support portion is arranged vertically. The foaming injectionhole through which the thermal insulator is injected may be provided onat least one of the upper surface, the lower surface, the left side andthe right side of the frame assembly. Meanwhile, at the temporaryassembly step, the panel assembly may temporarily be assembled in thecenter portion.

According to further still another aspect of the present invention, adoor for a refrigerator comprises a support portion surrounding anopened center portion, having a thermal insulator received in thesupport portion, wherein a foaming injection hole through which thethermal insulator is injected is provided to foam the thermal insulatorin a long length direction of the support portion.

The foaming injection hole is preferably provided on at least one of theupper surface, the lower surface, the left side and the right side ofthe support portion. More preferably, the support portion isrespectively provided at both ends. Meanwhile, the panel assembly may beprovided at the center portion.

To achieve the aforementioned object, according to one embodiment of thepresent invention, a door for a home appliance comprises a panelassembly; and a frame assembly having an opening connected with an edgeof the panel assembly to support the panel assembly, and making afoaming space for receiving a thermal insulator between edges of theframe assembly and the panel assembly, wherein a foaming injection holethrough which the thermal insulator is injected is provided on at leastone of ends of an upper surface, a lower surface, a left side and aright side of the frame assembly.

The frame assembly may include a rear frame located on a rear surface ofthe door, and a side frame connected with the rear frame, making thefoaming space.

The panel assembly may include two or more glass panels and a spacerprovided between edges of the two glass panels, and a heating elementmay be provided near the spacer.

The frame assembly may have a depth substantially the same as that ofthe panel assembly.

The frame assembly may have a width of 35 mm or less.

The foaming injection hole may be provided at both ends of the frameassembly.

The foaming injection hole is preferably provided on at least one of theends of the upper surface and the lower surface of the frame assembly.In this case, it is preferable that a width of the upper surface and thelower surface of the frame assembly is smaller than that of the left andright sides of the frame assembly. That is, in a state that the door isarranged vertically, the door may be formed in a rectangular shapehaving a height greater than a left and right width.

Preferably, the foaming injection hole is provided at an end of thelower surface of the frame assembly.

The foaming injection hole is preferably provided at both ends of thelower surface of the frame assembly.

Preferably, the foaming injection hole is provided in a long lengthdirection of the frame assembly. In case of a rectangular shape doorhaving an upper and lower height greater than a left and right width, itis preferable that a foaming direction through the foaming injectionhole is a vertical direction.

To achieve the aforementioned object, according to one embodiment of thepresent invention, a refrigerator comprises a cabinet constitutingappearance of the refrigerator; a main door rotatably coupled to thecabinet; and a sub door rotatably coupled to the main door, wherein thesub door includes a panel assembly; and a frame assembly having anopening connected with an edge of the panel assembly to support thepanel assembly, and making a foaming space for receiving a thermalinsulator between edges of the frame assembly and the panel assembly,wherein a foaming injection hole through which the thermal insulator isinjected is provided on at least one of ends of an upper surface, alower surface, a left side and a right side of the frame assembly.

To achieve the aforementioned object, according to one embodiment of thepresent invention, a door for a home appliance comprises a frameassembly surrounding an edge of the panel assembly to support the panelassembly, forming a foaming space with the panel assembly, and a foaminginjection hole provided on at least one of ends of an upper surface, alower surface, a left side and a right side of the frame assembly toinject a thermal insulator in a length direction of the frame assembly.

After the panel assembly and the frame assembly are temporarilyassembled, it is preferable that the panel assembly is fixed to theframe assembly by a foaming press by foaming of the thermal insulator.

Preferably, the foaming injection hole is provided to inject a foamingagent in a longer length direction of a horizontal length or a verticallength of the frame assembly.

The foaming injection hole is preferably formed such that a foamingdirection of the foaming agent is substantially the same as a gravitydirection.

To achieve the aforementioned object, according to one embodiment of thepresent invention, a door for a home appliance comprises a panelassembly including a front panel and a rear panel; a frame assemblyincluding a rear frame connected with the rear panel, and a side frameconnecting the rear frame with the front panel; a thermal insulationspace formed between the frame assembly and the panel assembly,receiving a thermal insulator therein; and a foaming injection holeprovided to foam the thermal insulator to at least one of ends of anupper surface, a lower surface, a left side and a right side of theframe assembly in a length direction of the frame assembly, wherein therear frame is partially inserted into the side frame and coupled to theside frame to increase a coupling force between the rear frame and theside frame by means of an expansion pressure of the thermal insulatorexpanded in the foaming direction and a vertical direction.

The side frame includes a heat bridge extended to an inner side of aradius direction along a rear surface of the front panel, the heatbridge being formed in parallel with the rear surface of the frontpanel.

Preferably, a hot wire is provided between the heat bridge and the rearsurface of the front panel and is tightly adhered to the front panel.

The hot wire is provided to be tightly adhered to the front panelthrough a metal sheet to block inflow of the thermal insulator to thehot wire, and its position is fixed by the pressure of the thermalinsulator applied to the metal sheet.

A center portion of the panel assembly corresponding to the inner sideof the radius direction of the frame assembly may be a see-through areaof the door or a touch area to which a touch input of a user is applied.

To achieve the aforementioned object, according to one embodiment of thepresent invention, a door for a home appliance and a home applianceincluding the same, the door comprising: a panel assembly of arectangular shape having a height greater than a left and right width; aframe assembly surrounding an edge of the panel assembly to support thepanel assembly, forming a foaming space with the panel assembly, andincluding an upper frame, a lower frame, and both side frames; and afoaming injection hole provided at each of left and right ends of thelower frame to inject a thermal insulator to the foaming space.

One side of the frame assembly is opened, and the opened portion isblocked by the panel assembly. Therefore, the frame assembly surroundsthe panel assembly along the edge of the panel assembly. Also, a foamingspace filled with the foaming agent may be formed between the frameassembly and the panel assembly.

That is, the frame assembly and the panel assembly may be coupled toeach other by the foaming agent which is filled, instead of directcoupling between the frame assembly and the panel assembly. In otherwords, coupling between the frame assembly and the panel assembly may becompleted by foaming after temporary assembly between the frame assemblyand the panel assembly.

The foaming injection hole may include a first injection hole providedat a direct lower portion of the side frame, and a second injection holeprovided to be inclined toward an inner side of the door from the directlower portion of the side frame. Preferably, the first injection holeand the second injection hole are formed on the upper frame or the lowerframe, which forms the upper surface or the lower surface of the frameassembly.

Therefore, since injection may be performed in one direction, aninjection device may easily be manufactured and also injection mayeasily be performed.

The first injection hole is provided to perform foaming in the samemanner as a length direction of the first side frame of both sideframes, the first side frame having a greater sectional area of thefoaming space, and the second injection hole is provided to be inclinedtoward the inner side of the door in a length direction of the secondside frame having a smaller sectional area of the foaming space to allowa foaming agent injected through the second injection hole to move tothe foaming space formed by the lower frame and then move to the foamingspace formed by the second side frame.

If the foaming agent is injected after the door is arranged reversely(the foaming injection hole is arranged at an upper portion), thefoaming agent injected through the first injection hole may initiallymove to the lower portion vertically and then move horizontally. Thefoaming agent injected through the second injection hole may initiallymove horizontally and then move to the lower portion vertically.

The frame assembly supports the panel assembly at the rear of the panelassembly, includes a rear frame for forming the foaming space betweenthe panel assembly and the upper frame, the lower frame and both sideframes.

The rear frame is preferably provided with vent holes formed todischarge out the air inside the foaming space during foaming. In thiscase, the rear frame is located vertically with respect to a movingdirection of the foaming agent. That is, at the rear frame located atthe rear of the panel assembly, the vent holes are preferably formeddischarge the air out to the rear of the door. Therefore, the air notthe foaming agent may be discharged out more actively.

The rear frame may be provided with a gasket mounting groove on which agasket is mounted, and the gasket mounting groove maybe provided withvent holes formed to discharge out the air inside the foaming spaceduring foaming.

The gasket is mounted on the gasket mounting groove, and thus the gasketmounting groove is covered by the gasket. Therefore, the vent holesformed in the gasket mounting groove are covered by the gasket.Therefore, since the vent holes are not exposed to the outside, estheticappearance of the door is not damaged.

Also, the foaming injection hole may be covered after foaming. Forexample, a cover coupled with the lower frame may be provided. That is,if foaming is completed, the cover is coupled with the lower frame,whereby the foaming injection hole may be covered.

Advantageous Effects

Advantageous effects of the door for the refrigerator, the refrigeratorand the method for manufacturing the same as described above may be asfollows.

First of all, according to the present invention, since foamingresistance may be reduced when a temporarily assembled door is foamedwith a thermal insulator, the thermal insulator may be prevented frombeing less filled in the frame assembly.

Secondly, according to the present invention, since foaming resistancemay be reduced when a temporarily assembled door is foamed with athermal insulator, the thermal insulator which is a foaming agent may beprevented from being leaked to the foaming injection hole or the panelassembly while being swollen. Also, the thermal insulator which is thefoaming agent may be prevented from flowing backward to the foaminginjection hole.

Thirdly, according to the present invention, since the temporarilyassembled door is arranged vertically to foam the thermal insulator, thethermal insulator, which is the foaming agent, more effectively moves toa foaming path by means of gravity, whereby foaming performance may beimproved.

BRIEF DESCRIPTION OF THE DRAWINGS

Arrangements and embodiments will be described in detail with referenceto the following drawings in which like reference numerals refer to likeelements and wherein:

FIG. 1 is a perspective view illustrating an example of a refrigeratoraccording to the embodiment of the present invention;

FIG. 2 is a perspective view illustrating a door of FIG. 1 to describethe principle of the embodiment of the present invention;

FIG. 3 is a sectional view taken along line I-I of FIG. 1;

FIG. 4 is a preferred exploded perspective view illustrating a door ofFIG. 1;

FIG. 5 is a perspective view illustrating movement of a foaming agentduring injection of the foaming agent to a door of FIG. 1;

FIG. 6 is a perspective view illustrating a moving direction of afoaming injection hole and a foaming agent in a door according to oneembodiment of the present invention; and

FIG. 7 is a perspective view illustrating arrangement of vent holes at adoor shown in FIG. 6.

DETAILED DESCRIPTION

Hereinafter, the preferred embodiment of the present invention will bedescribed with reference to the accompanying drawings. Hereinafter, forconvenience of description, a bottom freezer type refrigerator will bedescribed. Of course, the present invention is not limited to the bottomfreezer type refrigerator, and may be applied to a top mount typerefrigerator, a side by side type refrigerator, etc. Also, forconvenience of description, a refrigerator provided with a refrigeratordoor having a main door and a sub door 2 will be described exemplarily.Of course, the present invention is not limited to the refrigerator, andmay be applied to a refrigerator having one refrigerator door. That is,the present invention may be applied to all refrigerators each having adoor provided with a panel assembly.

First of all, a whole configuration of a preferred embodiment of arefrigerator according to the present invention will be described withreference to FIG. 1. In this embodiment, the number of doors,installation type, etc. are not main subjects of this embodiment, andthus will briefly be described within the range that assistsunderstanding of the present invention.

A refrigerator compartment is provided at an upper portion of a cabinet1, and a freezer compartment is provided at a lower portion of thecabinet 1. Doors 3, 5, 9 and 11 are rotatably installed at upper andlower portions of the cabinet 1 to open or close the refrigeratorcompartment and the freezer compartment. The doors may be hingedlycoupled to the cabinet. Although two doors 3, 5, 9 and 11 forrespectively opening or closing the refrigerator compartment and thefreezer compartment are shown in this embodiment, one door may be usedwithout limitation to this embodiment. Also, although a main door 5 anda sub door 7 are shown as right doors for the refrigerator compartmentin this embodiment, one door may be used as a right door for therefrigerator compartment without limitation to this embodiment.

According to this embodiment, the right door for the refrigeratorcompartment includes a main door 5 rotatably coupled to the cabinet 1,and a sub door 7 rotatably coupled to the main door 5. Since the maindoor 5 is provided with another side storage space such as a basket, auser may approach storage goods kept in the side storage space byopening the sub door 7 only without opening the main door 5.

The sub door 7 according to this embodiment includes a panel assembly 10through which a user may see from the outside of the refrigerator, and aframe assembly 20 for supporting the panel assembly 10. The sub door mayalso include an insulation space that is provided based on the panelassembly and the frame assembly. Preferably, the panel assembly 10 haspredetermined insulation performance by using insulation glass, etc.,and the frame assembly 20 has predetermined insulation performance. Toavoid dew formation at a connection portion 2 between the panel assembly10 and the frame assembly 20, it is preferable that a heating element 30is provided at the connection portion between the panel assembly 10 andthe frame assembly 20 (detailed structure of panel assembly, frameassembly and heating element will be described later).

Referring to FIG. 2, the principle of the embodiment of the door for therefrigerator according to the present invention will be described. Thesub door 7 described in this embodiment is only one example of the doorhaving the panel assembly 10. Therefore, the sub door 7 will be referredto as “door” for convenience of description except that the sub door 7should be provided as a special door. FIG. 2 briefly illustrates thedoor 7 having the panel assembly 10 to describe the principle of thepresent invention. Also, the rear surface of the door 7 is shown as anupper portion.

As described above, the door 7 includes a panel assembly 10, a frameassembly 20 for supporting the panel assembly 10, and a thermalinsulator 60 (or insulation space) defined by the frame assembly andfoamed in a foaming space. Preferably, the panel assembly 10 is, but notlimited to, approximately rectangular shape to correspond to the shapeof the door. Preferably, the frame assembly 20 supports an edge 11 a ofthe panel assembly 10. For example, the frame assembly 20 defines afoaming space having an opening 21, and the panel assembly 10 ispreferably connected to the opening 21 (see FIG. 3).

Meanwhile, in case of a door having no panel assembly 10, a foamingspace becomes a size of the door, that is, “left and right width DW2 ofthe door x upper and lower width DW2 of the door x depth DH of thedoor”. Also, the foaming space briefly becomes a foaming path. However,in case of the door 7 having the panel assembly, a space substantiallymade by the frame assembly 10 becomes a foaming space. The foaming spacebecomes a space excluding the size of the panel assembly 10 from thesize of the door 7. The size of the panel assembly 10 becomes “left andright width GW1 of the panel assembly x upper and lower width GW2 of thepanel assembly x depth GH of the panel assembly”. Also, since the frameassembly 10 is connected to the edge 11 a of the panel assembly 10, aspace made between the edge 11 a of the panel assembly 10 and an edge 20a of the frame assembly 20 becomes a foaming space. Therefore, a leftand right width FW1 of the frame assembly 20 becomes a differencebetween the left and right width DW1 of the door 7 and a left and rightwidth GW1 of the panel assembly 10, and an upper and lower width FW2 ofthe frame assembly 20 becomes a difference between the upper and lowerwidth DW2 of the door 7 and an upper and lower width GW2 of the panelassembly 10. Although the depth of the frame assembly 20 may bedifferent from the depth DH of the door 7, it is preferable that thedepth of the frame assembly 20 is approximately the same as the depth DHof the door 7. Also, it is preferable that the depth of the frameassembly 20 is the same as or greater than the depth GH of the panelassembly 10.

Generally, the size of the door 7 is previously determined in accordancewith the refrigerator, and it is preferable that the size of the panelassembly 10 is great if possible. This is because that the user mayeasily see the inside of the refrigerator through the panel assembly 10if the size of the panel assembly 10 is great. Therefore, ifrequirements of the door such as rigidity and insulation are within asatisfactory range, the size of the panel assembly 10, particularly theleft and right width GW1 and the upper and lower width GW2 are close tothe left and right width FW1 and the upper and lower width DW2 of thedoor, whereby it is preferable that the left and right width FW1 and theupper and lower width DW2 of the frame assembly 20 are small. Therefore,it is preferable that the difference between the upper and lower widthDW2 of the door 7 and the upper and low width GW2 of the panel assembly10 and the difference between the left and right width DW1 of the door 7and the left and right width GW1 of the panel assembly 10 are relativelysmall.

That is, it is preferable that an interval between the edge 11 a of thepanel assembly 10 and the edge 20 a of the frame assembly 20, that is,the widths FW1 and FW2 of the frame assembly 20 are relatively narrow.If the size of the panel assembly 10 is maximized while another designcondition of the door 7 is being satisfied, it is preferable that thewidths FW1 and FW2 of the frame assembly 20 are minimized and the depthDH of the frame assembly 20 is minimized. This means that the foamingpath becomes smaller than the width of the foaming path allowable in thethermal insulator foaming method of the related art. To this end, thedepth DH and the widths FW1 and FW2 of the frame assembly 20 may beabout 35 mm or less, for example.

Meanwhile, the foaming space where the thermal insulator 60 is foamedbecomes a space mainly made by the frame assembly 20. However, asdescribed above, it is preferable that the widths FW1 and FW2 of theframe assembly 20 are relatively narrow in view of the properties of theframe assembly 20. Therefore, in case of the panel assembly door 7, thefoaming space and the foaming path are relatively smaller than those ofthe door having no panel assembly. Therefore, in accordance with therelated art, if the foaming injection hole (for example, A1) is providedon a rear surface of the frame assembly 20 and the thermal insulator 60is injected through the foaming injection hole A1, a problem may occurin foaming performance. This is because that the foaming interval of thedoor 7 according to the present invention is narrower than the foaminginterval allowable in the foaming method of the related art and thusfoaming resistance may be increased to cause a problem in foamingperformance.

That is, since the depth DH and the width FW1 of the frame assembly 20are small, foaming resistance is great and thus a filling time isincreased and the foaming agent may not be filled fully. Also, thefoaming agent may be leaked to the foaming injection hole A1 or thepanel assembly 10. Therefore, in this embodiment, it is preferable thatfoaming injection holes B1, B2, B3, B4 and B5 are arranged atpredetermined positions corresponding to at least one of a left side, aright side, an upper surface and a lower surface not front and rearsurfaces of the frame assembly 20.

The foaming injection holes B1, B2, B3, B4 and B5 of the door 7 for therefrigerator according to the present invention will now be described indetail.

As described above, it is preferable that the foaming injection holesB1, B3, B3, B4 and B5 are provided on at least one of the left side, theright side, the upper surface and the lower surface (hereinafter,comprehensively referred to as “side” except that the respective sidesof the frame assembly 20 should be categorized specially from oneanother) of the frame assembly 20. (the foaming injection holes at theleft side and the lower surface are shown in FIG. 2). Also, it is morepreferable that the foaming injection holes B2, B3, B4 and B5 areprovided on ends of the upper surface, the lower surface, the left sideand the right side of the frame assembly 20. This is because that if thefoaming injection hole B1 is located at the center of the side of theframe assembly 20, the distance FW1 between the panel assembly 10 andthe foaming injection hole B1 is short, and thus foaming is slowlyperformed in a length direction L (orthogonal direction of the foamingdirection). Also, in this case, the foaming agent may be leaked alongthe direction of the panel assembly 10. Therefore, it is preferable thatthe foaming injection holes B2, B3, B4 and B5 are located toward the endof the frame assembly 20 instead of the center of the frame assembly 20.

Meanwhile, as described above, the foaming injection holes B2, B3, B4and B5 may be located at the side of the frame assembly 20, that is,ends of the left side, the right side, the upper surface and the lowersurface. However, in case of the foaming injection holes B2 and B3 (thefoaming injection hole of the left side is only shown in FIG. 2) locatedat the right side and the left side of the frame assembly 20, althoughthe thermal insulator may be foamed without relative foaming resistance,the foaming injection holes B2 and B3 are exposed after foaming, wherebyit is not good in view of esthetic appearance. This is because that theright side and the left side of the frame assembly 20 constituteexternal appearance of the door 7, and the foaming injection holes B2and B3 may be seen to a user when the door 7 is opened or closed. Also,a hinge structure (not shown) for connecting the door 7 to the cabinetof the refrigerator to open or close the door 7 is coupled to upper andlower ends of the right side or the left side of the frame assembly 20.Therefore, if the foaming injection holes B2 and B3 are located at theends of the right side and the left side of the frame assembly 20, thehinge structure may be foaming resistance during foaming of the thermalinsulator. Therefore, it is more preferable that the foaming injectionholes B4 and B5 (the foaming injection hole of the lower surface is onlyshown in FIG. 2) are provided at the ends of the upper surface and thelower surface instead of the ends of the left side and the right side ofthe frame assembly 20.

Meanwhile, as described above, if the foaming injection holes B4 and B5are provided at the ends of the upper surface and the lower surface ofthe frame assembly 20, there is no problem in foaming task of thethermal insulator. However, parts such as a sensor, a PCB, and a magnetare installed at the end of the upper surface of the frame assembly 20.Therefore, if the foaming injection hole (not shown) is located at theend of the upper surface of the frame assembly 20, the position of thefoaming injection hole should be selected to avoid the above parts, andthe above parts may be foaming resistance. Also, the foaming injectionhole located at the end of the upper surface of the frame assembly 20may be exposed to the outside during opening of the door. Particularly,in case of the door installed at the lower portion of the refrigerator,if the door is opened, the foaming injection hole is seen to a user,whereby it is not good in view of esthetic appearance. Therefore, it ismore preferable that the foaming injection holes B4 and B5 are locatedat the end of the lower surface of the frame assembly 20.

Meanwhile, one foaming injection hole B4 or B5 may be provided at oneend of the lower surface of the frame assembly 20, or two foaminginjection holes B4 and B5 may respectively be provided at both ends. Ifone foaming injection hole is provided, it is preferable that a positionfavorable for obtaining foaming quality is selected. For example, in thesame manner as the embodiment shown in FIG. 3, if an indentation 330that serves as a handle is provided at one side of the frame assembly20, it is preferable that the foaming injection hole B4 is selected atthe end of an opposite portion. This is because that the foaminginjection hole B5 may be partially overlapped with the edge of the frameassembly 20 if the foaming injection hole B5 at the portion where theindentation 330 serving as a handle is provided is selected. Therefore,since a part of the foaming agent is in contact with the edge portion ofthe frame assembly 20, the foaming agent may flow backward. On the otherhand, if the foaming injection hole B4 at the portion where theindentation 330 is not formed is selected, since the foaming injectionhole B4 is not partially overlapped with the frame assembly 20, thefoaming agent may be prevented from flowing backward (see FIG. 5). Ofcourse, if there is no problem as the indentation 330 is not provided inaccordance with the structure of the door, the foaming injection holemay be selected regardless of the left and right sides.

Meanwhile, as described above, the foaming agents B4 and B5 mayrespectively be provided at both ends of the frame assembly 20. Even inthis case, in the same manner as the embodiment shown in FIG. 3, if theindentation 330 serving as a handle at one side of the frame assembly 20is provided, the foaming agent flown to the foaming injection hole B5 atthe portion where the indentation 330 is provided may flow backward. Toavoid this, it is preferable that the width of the lower surface of theframe assembly 20 where the foaming injection holes B4 and B5 areprovided is greater than the widths of the left side portion, the rightside portion and the upper surface portion. If the width of the leftside portion, the right side portion and the upper surface portion ofthe frame assembly 20 is smaller than 35 mm, it is preferable that thewidth of the lower surface portion is greater than 35 mm. For example,if the width of the left side portion, the right side portion and theupper surface portion of the frame assembly 20 is 25 mm, it ispreferable that the width of the lower surface portion is 45 mm. In thiscase, since the foaming agent flown to the foaming injection hole B5 isrelatively great and may be guided to the portion where foamingresistance is small, leakage of the foaming agent may be avoided.

Referring to FIGS. 3 and 4, the preferred embodiment of the dooraccording to this embodiment will be described in detail. The sub door 7described in this embodiment is an example of the door having the panelassembly. Therefore, the sub door 7 is referred to as a door forconvenience of description except that the sub door 7 is categorized asa special door in the following description.

It is preferable that the panel assembly 10 of the door 7 haspredetermined insulation performance. Preferably, the panel assembly 10is, but not limited to, approximately rectangular shape to correspond tothe shape of the door. Preferably, the frame assembly 20 supports theedge of the panel assembly 10, and has predetermined insulationperformance. It is preferable that the heating element 30 is provided ata portion, that is, connected portion 10 a, where the panel assembly 10and the frame assembly 20 are mutually connected to each other. That is,the heating element 30 may be provided at a predetermined position ofthe connected portion 10 a between the panel assembly 10 and the frameassembly 20. Also, if the connected portion 10 a between the panelassembly 10 and the frame assembly 20 may substantially be heated, theheating element 30 may be installed at a predetermined distance from theconnected portion 10 a.

Each element of the door will be described in detail.

First of all, an example of the panel assembly 10 will be described.

As illustrated in FIG. 3, the panel assembly 10 may include a frontpanel 16. The front panel 16 defines the front surface of the door 7.The front panel 16 is made of a transparent material to allow a user tosee through the front panel 16. The front panel 16 is made of a touchpanel to allow a user to control an operation of a home appliancethrough the touch panel. The front panel 16 may be a glass panel. Thatis, the front panel 16 may be a glass panel even if the front panel 16is a transparent panel or a touch panel.

The inner space of the panel assembly, which is defined by the panelassembly 10, may be an insulating space provided at the rear of thefront panel 16. For example, as shown in FIG. 3, the panel assembly 10may include an intermediate panel 14 and a rear panel 12 to improveinsulation performance. However, without limitation to the example shownin FIG. 3, a number of the panels may be varied and/or another typethermal insulating panel may be provided. Therefore, the panel assembly10 may include the front panel 16 and a thermal insulating panelprovided at the rear of the front panel. In case of the transparentpanel assembly 10 shown in FIG. 3, the front panel 16, the intermediatepanel 14 and the rear panel 12 may be glass panels, and a space amongthe panels is sealed by a proper gas. In case of the touch panelassembly 10, an inner space defined by the panel assembly 10 may includeone or a plurality of sensors, for example, sensors for sensing a touchinput applied to the front panel 16, such as a touch sensor and anelectromagnetic sensor.

For example, the front panel 16 may be formed to be greater than theother portion of the panel assembly 10. In the example shown in FIG. 2,the front panel 16 is greater than the intermediate panel 14 and therear panel 12. For example, the front panel 16 may substantially be thesame as the size of the door 7, and may cover the frame assembly 20 whenviewed at the front of the refrigerator. As described above, since thefront panel 16 defines a front appearance of the door 7, the front panel16 may have the same size as that of the door and provide very estheticappearance. The front panel 16 may provide appearance of the door seento a user like that the door is formed as a single panel. To this end,the front panel 16 has a peripheral portion or an extension portion(peripheral front panel portion) 16 a. The extension portion may be aportion extended from an outer edge of the rear panel 12 or theintermediate panel to all directions.

First of all, the panel assembly 10 will be described as follows. It ispreferable that the panel assembly 10 includes two or more panels 12, 14and 16 to obtain predetermined insulation performance. The panel may beformed of a glass material. A spacer 18 for maintaining intervals amongthe panels 12, 14 and 16 is provided at the edges of the panels 12, 14and 16, and it is preferable that the panels 12, 14 and 16 are coupledto one another by using a sealant 19. That is, the space among thepanels may be sealed through the sealant 19.

Preferably, thermal insulation glass having predetermined insulationperformance is used as the plurality of panels 12 and 14. Of course, twoor more thermal insulation glasses may be used. Moreover, low-e glass ispreferably used as the thermal insulation glasses 12 and 14 to shieldheat loss caused by radiation. Although a hard low-e glass and a softlow-e glass may be used as the low-e glasses, it is preferable that thesoft low-e glass is used to obtain more excellent low-e performance.

Since the front panel 16 located at the front of the plurality of panels12, 14 and 16 is located at the front of the door 7 to form appearanceof the door 7, a tempered glass is preferably used to avoid damage.Also, it is preferable that glass (hereinafter, referred to as“discolored glass”) through which a user may selectively see the insideof the refrigerator by controlling light transmittance is used as thefront panel 16. That is, when a lamp inside the refrigerator is turnedoff, it is preferable that the front panel 16 becomes an opaque state toallow a user not to see the inside of the refrigerator externally. Whenthe lamp inside the refrigerator is turned on, it is preferable that thefront panel 16 becomes a transparent state to allow a user to see theinside of the refrigerator externally. Also, the front panel 16 having acoloring function is not limited to a special glass, and a color glassmay be used as the front panel 16, or an opaque coated glass by TIdeposition may be used as the front panel 16. Of course, it ispreferable that the front panel 16 has insulation performance.

Meanwhile, it is preferable that the front panel 16 has a size greaterthan those of the other panels 12 and 14, that is, the intermediatepanel 14 and the rear panel 12. For example, it is preferable that thefront panel 16 has approximately the same size as that of the door. Asdescribed above, since the front panel 16 of the panel assembly 10becomes appearance of the door 7, if the size of the front panel 16 isthe same as that of the door 7, the whole door 7 is seen to a user asglass, whereby esthetic appearance is improved. To this end, the frontpanel 16 has an extension portion 16 a which becomes a portion extendedfrom the portion corresponding to the edges of the rear panel 12 and theintermediate panel 14 to a width direction of left and right sides ofthe door. In this case, since the whole door is seen to a user as aglass, esthetic appearance may be improved.

Although Al or a thermal protection spacer (TPS) may be used as thespacer 18, the TPS is preferably used as the spacer 18 to improveinsulation performance at the portion where the spacer 18 is installed.It is preferable that a moisture absorbent is provided inside the spacer18.

Meanwhile, a vacuum state may become between the rear panel 12 and theintermediate panel 14 and between the intermediate panel 14 and thefront panel 16, or the air or Ar gas may be filled between the rearpanel 12 and the intermediate panel 14 and between the intermediatepanel 14 and the front panel 16. Since the Ar gas is an inert gas whichhas insulation performance more excellent than that of the air and canbe prevented from being changed by a chemical action, it is preferablethat the Ar gas is used instead of the air.

Next, the frame assembly 20 will be described in detail.

Preferably, the frame assembly 20 has predetermined insulationperformance. To this end, the frame assembly 20 may include, but notlimited to, a portion for supporting the door at a predeterminedrigidity for supporting the panel assembly 10, and a portionsubstantially serving as a thermal insulation function. The frameassembly 20 defines a thermal insulation space for receiving a thermalinsulator 60 having predetermined thermal insulation performance, and ispreferably coupled to the panel assembly 10.

Preferably, the frame assembly 20 includes, but not limited to, aplurality of parts considering convenience of assembly of the door.First of all, the whole configuration of an example of the frameassembly 20 will be described with reference to FIG. 3.

The frame assembly 20 includes a rear frame 200 located at the rear ofthe door. Also, the frame assembly 20 includes side frames 300 and 400located at left and right sides of the door, an upper frame 500 locatedon an upper end of the door, and a lower frame 600 located at a lowerend of the door. For example, the panel assembly 10 is transparent, andthe rear frame 200, the side frames 300 and 400, the upper frame 500 andthe lower frame 600 define a thermal insulation space together with thepanel assembly 10. That is, these frames define the thermal insulationspace along upper and lower and left and right corners of the panelassembly 10 together with the panel assembly 10. In an example of asee-through transparent panel assembly 10, the thermal insulation spacemay receive the thermal insulator 60. An example of the thermalinsulator may include a thermal insulation foam or another materialthermal insulator or a thermal insulation gas. The panel assembly 10 maybe connected to an opening defined by inner corners of the rear frame200, the side frames 300 and 400, the upper frame 500 and the lowerframe 600. For example, if the panel assembly 10 is transparent, sidecorner portions of the panel assembly 10 and the space defined by theframes may be filled with the thermal insulator (see FIG. 3).Alternatively, if the panel assembly is a touch panel, a space betweenthe rear panel 12 and the intermediate panel 14 may be filled with thethermal insulator.

Preferably, the rear frame 200 is located at an inner side of the door,and serves to support the whole door. The frames 300, 400, 500 and 600are located at upper and lower and left and right portions of the panelassembly 10, and may constitute a part of external appearance of thedoor. The frames 300, 400, 500 and 600 prevent distortion of the doorfrom occurring, and preferably serve to prevent dew formation fromoccurring at the door together with the thermal insulator 60.

The frames 300, 400, 500 and 600 may constitute a part of externalappearance of the door, and for example, may be regarded as a decorativetrim that can be seen outside the door.

The rear frame 200, the side frames 300 and 400 and their mutualrelationship will be described with reference to FIG. 3 again.

Mutual relationship among the panel assembly 10, the rear frame 200, theupper frame 500, and the lower frame 600 may have a similar structure.For convenience of description, a basis structure of the rear frame 200and the side frames 300 and 400 will be described herein, and a moredetailed structure thereof will be described in the followingembodiment, that is, the embodiment of a modified structure of the frameassembly.

Preferably, the rear frame 200 includes a first end 220 connected withthe panel assembly 10, a second end 230 connected to the side frames 300and 400, and a connecting portion 210 connecting the first end 220 withthe second end 230. The first end 220 of the rear frame 200 is a portionconnected to the rear panel 12 of the panel assembly 10, and the secondend 230 is a portion connected to the side frame. It is preferable thatthe connecting portion 210 connecting the first end 220 with the secondend 230 is approximately parallel with the front surface of the cabinetof the refrigerator. It is preferable that a gasket 40 is installed at apredetermined portion 235 of the rear frame 200 and its inner side isapproximately parallel with the portion 210 for connecting both ends ofthe rear frame 200. Meanwhile, it is preferable that the first end 220of the rear frame 200 is connected to the rear panel 200 to support therear panel 200. Also, it is more preferable that the first end 220 ofthe rear frame 200 is provided to surround the spacer 18 which isvulnerable to thermal insulation. In other words, it is preferable thatthe first end 220 is located at the inner side more inwardly than thespacer 18 in a radius direction.

The side frame 400 (for example, right frame) may include a rear frameconnecting portion 420 connected with the rear frame 200, and a panelconnecting portion 410 extended from the rear frame connecting portion420 and adjacent to the outside of the panel assembly 10, preferably theextension portion 161. It is preferable that the panel connectingportion 410 of the side frame 400 is connected to an end of theextension portion 16 a of the front panel 16.

The side frame 300 (for example, left frame) may include a rear frameconnecting portion 320 connected with the rear frame 200, and a panelconnecting portion 310 extended from the rear frame connecting portion320 and adjacent to the outside of the panel assembly 10, preferably theextension portion 161. The left side frame 300 includes an indentation330 indented toward the inner side of the door between the rear frameconnecting portion 320 and the panel connecting portion 310. Theindentation 330 may serve as a handle of the door. In this case, it ispreferable that a front end of the extension portion 16 a connected withthe left frame 300 in the extension portion 16 a of the front panel 16is located at the inner side more inwardly than the rear frameconnecting portion 320 to make a space into which a hand of a user maybe inserted. That is, it is preferable that the width of the extensionportion 16 a connected with the left frame 300 in the extension portion16 a of the front panel 16 is smaller than the width of the left frame300. Also, in this case, the first end of the left frame 300, that is, atransparent window connecting portion 310 starts at the position spacedapart from the front end of the extension portion 16 a of the frontpanel 16 toward the inner side, is extended to a front end direction andtightly adhered to the inner surface of the extension portion 16 a.

Meanwhile, as described above, the rear frame 200, the side frames 300and 400, the upper frame 500 and the lower frame 600 may define apredetermined space, more particularly, edge portions of the frames 200,300, 400, 500 and 600 and the panel assembly 10 may define asubstantially sealed space. This space is foamed and filled with thethermal insulator 60, for example, polyurethane foam (PU foam), wherebythe frame assembly 20 has predetermined insulation performance. Forexample, if the panel assembly 10 is not transparent, for example, ifthe panel assembly 10 is a touch panel, this insulation space may befilled with thermal insulators filled in the inner space of the panelassembly 10.

Next, the heating element 30 will be described in detail.

As described above, dew formation may occur at the connected portion 10a of the panel assembly 10 and the frame assembly 20 instead of thepanel assembly 10 under a specific condition. Therefore, it ispreferable that dew formation prevents from occurring at this connectedportion than any other portions.

Dew formation may occur at the connected portion between the panelassembly 10 and the frame assembly 20 because the cool air isconcentrated on the connected portion due to relatively vulnerablethermal insulation performance caused by a difference in thermalinsulation performance between the panel assembly 10 and the frameassembly 20. Also, it is regarded that the portion where the spacer 18of the panel assembly 10 is installed in the connected portion 10 abetween the panel assembly 10 and the frame assembly 20 is particularlyvulnerable to thermal insulation performance.

For example, it is preferable that the heating element 30 is installednear the connected portion 10 a between the panel assembly 10 and theframe assembly 20, that is, at the connected portion 10 a or near theconnected portion 10 a. For example, as shown in FIG. 2, the heatingelement 30 may be installed in an area between the thermal insulator 60and the panel assembly 10. That is, the heating element 30 may beprovided between the thermal insulator 60 and the panel assembly 10along a side of the inner area of the panel assembly 10. It is morepreferable that the heating element 30 is installed to be close to thefront surface of the door 7. This is because that the heating element 30is installed at the position where the front portion of the door 7 maybe heated because dew formation occurs at the front of the panelassembly 10, that is, at the front portion of the door 7. To this end,for example, as shown in FIG. 3, the heating element 30 may be providedon a rear surface of the front panel 16 of the panel assembly 10. Inmore detail, the heating element 30 may be provided at a position of therear surface of the front panel 16, which is inclined toward theconnected portion 10 a.

For example, the heating element 30 may be installed at an area of theframe assembly 20 connected to the panel assembly 10. In more detail,the heating element 30 may be provided on an inner surface or an outersurface of the first end 220 of the rear frame 200 or may be provided onan inner surface or an outer surface of the panel connecting portion 310of the side frame 300. That is, the heating element 30 may be providedon at least one ‘B’ of the inner surface and the outer surface of thefront and rear ends 220 and 310 of the frame assembly 20. This isbecause that the portion B is a portion where the front and rear ends ofthe frame assembly 20 are mainly connected to the panel assembly 10.

Meanwhile, as described above, since the spacer 18 becomes the portionvulnerable to thermal insulation, the heating element 30 may beinstalled at the portion where the spacer 18 is installed, that is,inside the spacer 18, or may be installed in contact with the spacer 18or near the spacer 18. However, if the heating element 30 is inside thespacer 18, a moisture absorbent of the spacer 18 is detached therefrom,whereby dew condensation may occur inside the panel assembly 10. Also,since the spacer 18 is located inside the panel assembly 10, if theheating element 30 is installed inside the spacer 18 or in contact withthe spacer 18, a separate mounting structure is required and a separateline is required. Therefore, considering these matters, it is morepreferable that the heating element 30 is installed along the edge ofthe panel assembly 10. If the heating element 30 is installed along theedge of the panel assembly 10, it is advantageous that the heatingelement 30 is installed near the spacer 18 and at the same time theinstallation structure is simple.

Meanwhile, as described above, the heating element 30 is, but notlimited to, preferably installed near the connected portion 10 a betweenthe panel assembly 10 and the frame assembly 20. Even though the heatingelement 30 is a little spaced apart from the connected portion 10 a, theheating element 30 may be installed at any position on the panelassembly 10 if heat is transferred to the connected portion 10 a toprevent dew formation from occurring. That is, the position correspondsto the position where the heating element 30 transfers heat to theconnected portion 10 a to prevent condensation from occurring. Forexample, the heating element 30 may be provided on at least one of innerand outer surfaces of the extension portion 16 a, that is, the edge ofthe front panel 16 of the panel assembly 10.

Meanwhile, the heating element 30 may be provided to heat the connectedportion only between the panel assembly 10 and the frame assembly 20.Therefore, a pre-heating type hot wire having less power consumption maybe used as the heating element 30. Therefore, it is preferable that theheating element 30 may be provided in a hot wire type to surround theedge of the panel assembly 10. That is, it is preferable that theheating element 30 is a hot wire and has a shape corresponding to theshape of the edge of the panel assembly 10. If the entire panel assemblyis heated, power consumption of about 60 W or more is required. However,since the connected portion between the panel assembly 10 and the frameassembly 20 is heated in this embodiment, power consumption of 7 W orless is required. Therefore, power consumption may be lowered to ⅛.

For example, since the side frames 300 and 400 are located toward therear at the edge of the extension portion 16 a of the front panel 16,the side frames 300 and 400 may not be seen to a user when the userlooks at the door at the front of the door. Therefore, it is preferablethat the front panel 16 of the panel assembly 10 is the same as the sizeof the door. Of course, the front panel 16 may be formed in a planeshape or a curved shape. Also, the panel connecting portion 310 may beconnected to the rear surface of the extension portion 16 a of the frontpanel 16. Therefore, the panel connecting portion 310 is not seen to theuser. Also, the heating element 30 may be installed near the connectedportion 10 a between the panel assembly 10 and the frame assembly 20.

It is preferable that an opaque portion 50 is provided on an innersurface of the extension portion 16 a of the front panel 16 to allow theheating element 30 not to be seen from the outside of the door and theheating element 30 is located on an inner surface of the opaque portion50. The opaque portion 50 may easily be implemented by opaque printingof the inner surface of the front panel 16.

Meanwhile, the heating element 30 is preferably attached using anelement having thermal conduction property such as Al tape. If theheating element 30 is attached by Al tape, the heating element 30 maytemporarily be fixed during manufacture of the door, and may beprevented from being pushed into the panel assembly 10 during foaming ofthe thermal insulator 60. Also, heat of the heating element 30 mayeffectively be transferred to the periphery by the Al tape.

In more detail, heat generated from the heating element 30 mayeffectively be transferred to the peripheral portion of the front panel16 through the attachment element having thermal conduction property.Also, if the panel assembly 10 is see-through, the heating element 30may temporarily be fixed during manufacture of the door through theattachment element such as the Al tape. Therefore, the heating element30 may be prevented from moving during injection of the thermalinsulator 60. Of course, the thermal insulator may be prevented frombeing directly in contact with the heating element 30.

Also, the heating element 30 may tightly be fixed to the front panel 16by pressure of the thermal insulator.

Meanwhile, as shown in FIG. 3, the side frames 300 and 400 of the door 7may include heat bridges 315 and 415. The heat bridges 315 and 415 maybe provided together with the heating element 30, or may be providedwithout heating element.

The heat bridges 315 and 415 transfer external heat transferred from theside frames 300 and 400 to the inner area of the panel assembly 10. Thatis, the heat bridges 315 and 415 may be provided to transfer heat towardthe connected portion 10 a which is vulnerable to thermal insulation.The cool air inside the refrigerator may be transferred near theconnected portion 10 a through the spacer 18. Therefore, the heatbridges 315 and 415 may be heated through heat of the external air.

A method for manufacturing a door according to the present inventionwill be described with reference to FIGS. 4 and 5.

Foaming quality is affected by a length of a foaming path, a shape ofthe foaming path, a period change of the foaming path shape, and afilling time. That is, if the foaming path is long or a sectional areaof the foaming path is small, foaming resistance is increased and thefilling time is also increased in accordance with the increase of thefoaming resistance. Therefore, the foaming agent may not be fully filledor material property value such as mechanical strength and thermalinsulation performance may not be uniform per foaming period anddeviation may occur. Also, deviation of the material property valueoccurs per foaming period even in the case that there is a period changein the foaming path shape.

Considering this, the method for controlling the door according to thepresent invention will be described as follows. For convenience, foaminginjection holes B4 and B5 are respectively provided at both ends of thelower surface of the frame assembly 20.

First of all, the panel assembly 10 and the frame assembly 20 aretemporarily assembled to make a temporary assembly door 71, and athermal insulator is injected and foamed through the foaming injectionholes B4 and B5 of the temporary assembly door 71, whereby the door ismanufactured.

In more detail, the second frames 300, 400, 500 and 600 are assembled.That is, the upper deco 500 and the lower deco 600 are fixedly insertedinto the left deco 300 and the right deco 400 to make a temporarilyassembled frame assembly 20. Then, the panel assembly 10 is temporarilyfixed to the temporarily assembled frame assembly 20 by a double-sidedtape, and the first frame 200 is inserted thereto, whereby the temporaryassembly door 71 is made. It is preferable that the temporary assemblydoor 71 is arranged vertically. That is, it is preferable that the uppersurface of the temporary assembly door 71 is arranged in a grounddirection, whereby the foaming injection holes B4 and B5 provided on thelower surface of the frame assembly 20 are arranged on the upper portionof the temporary assembly door 71. In this state, a thermal insulator 60a of a foaming agent state is injected through the foaming injectionholes B4 and B5 of the frame assembly 20 for a predetermined time.

The temporary assembly door 71 is arranged vertically to inject thefoaming agent to the foaming injection holes B4 and B5 for the followingreasons. Even in the case that the foaming injection holes B4 and B5 arearranged on the upper surface or the lower surface of the temporaryassembly door 71, if the foaming agent is injected in a state that thetemporary assembly door 71 is arranged horizontally, foaming quality mayrelatively be deteriorated. If the foaming agent is injected in a statethat the temporary assembly door 71 is arranged horizontally, thefoaming agent injected to the foaming injection holes B4 and B5 isexpanded while moving along the foaming path from the foaming injectionholes B4 and B5. That is, the foaming agent is expanded while moving toa portion GS2 close to the foaming injection holes B4 and B5, and isalso expanded when moving to a portion GS1 far away from the foaminginjection holes B4 and B5. This is because that the foaming agent moveshorizontally without being affected by gravity. Therefore, the foamingagent injected at the portion GS1 farthest away from the foaminginjection holes B4 and B5 is finally expanded and coagulated, and a gastrap occurs there. Also, the foaming agent injected even at the portionGS2 close to the foaming injection holes B4 and B5 is expanded andcoagulated, whereby a gas trap occurs. Therefore, if the foaming agentis injected in a state that the temporary assembly door 71 is arrangedhorizontally, the foaming path is narrow and the gas trap occurs at twoportions by means of horizontal movement of the foaming agent, wherebytwo air vent holes are required. Also, incomplete filling of the foamingagent may occur due to the gas trap and path resistance.

However, even in the case that the foaming injection holes B4 and B5 arearranged on the upper surface or the lower surface of the temporaryassembly door 71, if the foaming agent is injected in a state that thetemporary assembly door 71 is arranged vertically, occurrence of the gastrap may be minimized and foaming quality may be improved. A foamingprocedure corresponding to the case where the foaming agent is injectedin a state that the temporary assembly door 71 is arranged verticallywill be described as follows.

The foaming agent injected to the two foaming injection holes B4 and B5moves to a half of all of the foaming paths. Also, the foaming agent 60a injected from the respective foaming injection holes B4 and B5 movesalong gravity and is collected on the lower surface LS. The foamingagent collected on the lower surface LS is expanded while upwardlymoving along a vertical path f1. The foaming agent moving to the upperportion is expanded while moving along a horizontal path f2 and finallyis fully filled in the foaming space. If the foamed thermal insulator iscoagulated, the manufacture of the door is finally completed. Therefore,if the foaming agent is injected in a state that the temporary assemblydoor 71 is arranged vertically, the gas trap may occur at only theportion GS2 where foaming is finally completed. As a result, one airvent hole is required, and incomplete filling of the foaming agent maybe avoided effectively.

Moreover, if the foaming agent is injected in a state that the temporaryassembly door 71 is arranged vertically in the same manner as theembodiment according to the present invention, the following advantagesare obtained. That is, if a left and right width FW1 of the frameassembly 20 is relatively small, for example, 35 mm or less, the foamingagent injected to the foaming injection holes B4 and B5 stained in theinner side of the frame assembly 20 while moving to the lower portion,whereby it is predicted that there may be a problem in foaming quality.However, unlike the prediction, even though the injected foaming agentis partially stained in the inner side of the frame assembly 20, thereis no problem in foaming quality. In this case, the foaming agent movingto the bottom of the frame assembly without being stained in the innerside of the frame assembly 20 and the foaming agent stained in the innerside of the frame assembly 20 are together foamed to enable uniformfoaming. That is, if the foaming agent is foamed vertically, a part ofthe foaming agent is stained in the inner side of the frame assembly 20using resistance caused by viscosity of the foaming agent, and the otherof the foaming agent reaches the lower surface LS, whereby it isadvantageous that foaming is simultaneously performed at the verticalportion and the lower portion to enable uniform foaming.

Also, if the two foaming injection holes B4 and B5 are used like thisembodiment, the foaming path is substantially reduced to a half and theshape change of the foaming path is reduced to a half. Also, the fillingtime is reduced. Therefore, incomplete filling of the foaming agent maybe avoided, and deviation of the material property value such as thermalinsulation performance and coupling rigidity may be minimized.

Meanwhile, although the foaming injection hole B4 is located at bothends of the lower surface of the frame assembly 20 in the aforementionedembodiment, the present invention is not limited to the aforementionedembodiment, and one foaming injection hole may be provided. If onefoaming injection hole is provided, that is, if one foaming injectionhole on the upper surface of the frame assembly 20 is provided, sincethe foaming path becomes the space formed by the frame assembly, thefoaming path is relatively long and filling time is relatively long.Also, sides of the frame assembly 20, that is, left side, right side,upper surface and lower surface have similar sectional shapes, which arenot completely the same as one another. This is because that the partsinstalled in the corresponding space are different from one another. Forexample, structures of the space where electronic units are installed,the space where hinge members are coupled, and the portion coupled tothe main door cannot be completely the same as one another. Therefore,although the panel assembly 10 and the frame assembly 20 are provided,their detailed shapes and dimensions may be different from each other(see sectional views of left side, right side, upper surface and lowersurface of FIG. 5). Therefore, as described above, if one foaminginjection hole is provided on the lower surface of the frame assembly20, it is preferable to select a position where foaming quality can bemaximized. For example, as shown in FIG. 5, if a handle is provided atone side of the frame assembly 20, it is preferable to select thefoaming injection hole B4 of the end of the opposite side.

The present invention is not limited to the aforementioned embodiment,and modifications can be made in the present invention by the personwith ordinary skill in the art to which the present invention pertains,within the scope of the present invention. For example, the presentinvention may be applied to the door having no panel assembly 10, forexample, the main door (see 5 of FIG. 1). The door will be describedwith reference to FIG. 1. In case of the main door 5, there is no panelassembly 10. In view of foaming, the substantial structure of the maindoor 5 is the same as the frame assembly 20 of the sub door 7. The maindoor 5 has a center portion 52 which is opened, and has an edgesurrounding the center portion 52, that is, a support portion 54, and athermal insulator is received in the space defined by the supportportion 54. The support portion 54 has predetermined rigidity to allowthe main door 5 to be rotatably connected with the cabinet 1 of therefrigerator, and has predetermined thermal insulation performance toallow the cool air inside the refrigerator not to leak out. Since thesupport portion 54 of the main door 5 is opened, the support portion 54has a width which is relatively small. Therefore, the foaming path maybe small and foaming resistance may be great. In this respect, thefoaming injection hole to which the thermal insulator is injected isprovided on at least one of the ends of the upper surface, the lowersurface, the left side and the right side of the main door 5, and it ispreferable that the foaming agent is injected after the main door 5 isarranged vertically in a temporary assembly state. Since the foamingprinciple is the same as that of the sub door 7, its detaileddescription will be omitted.

Also, although the size of the main door 5 is the same as that of thesub door 7 in the aforementioned embodiment, the present invention isnot limited to the aforementioned embodiment. For example, the presentinvention may be applied to even a case where the sub door 7 is smallerthan the main door 5.

Hereinafter, the foaming injection hole, a movement direction of thefoaming agent, and an air discharge relation for active movement of thefoaming agent will be described in detail with reference to FIGS. 6 and7. The position of the foaming injection hole in this embodiment may bea little different from the position of the foaming injection hole ofthe aforementioned embodiment.

Referring to the drawings, the foaming agent is injected to the firstinjection hole B5 and the second injection hole B4. At this time, thepressure of the foaming agent injected to the first injection hole B5may be different from the pressure of the foaming agent injected to thesecond injection hole B4. That is, the foaming agent injected to thefirst injection hole B5 through which the foaming agent moves to arelatively wide space may be injected at relatively high pressure.

The moving path of the foaming agent will be described with reference toFIG. 6. The foaming agent injected to the first injection hole B5 isinjected to the foaming space formed by the side frame 300 and the panelassembly 10. Then, the foaming agent moves to the foaming space formedby the lower frame 600 and the panel assembly 10.

The foaming agent injected to the second injection hole B4 is firstinjected to the foaming space formed by the lower frame 600 and thepanel assembly 10 and then moves to the foaming space formed by the sideframe 400 and the panel assembly 10.

The foaming agents simultaneously injected to the first injection holeB5 and the second injection hole B4 come across each other at thefoaming space formed by the upper frame 500 and the panel assembly 10 orthe foaming space formed by the side frame 400 and the panel assembly10.

Afterwards, after the foaming agent is fully filled in the foamingspaces formed by the upper frame 500 and the side frame 400 and the sideframe 300, the foaming agent may finally be filled in the space formedby the lower frame 600 and the panel assembly 10. Of course, if thefoaming agent is fully filled, the foaming injection holes B4 and B5 maybe blocked by a separate element such as an injection cover.

In this case, the filling direction of the first injection hole B5 maybe the same as a length direction of the side frame 300. It ispreferable that the filling direction of the first injection hole B5 isthe same as the length direction of the side frame 300. That is, themoving direction of the foaming agent injected through the firstinjection hole B5 is maintained in the same manner as the lengthdirection of the side frame 300 without being changed. Of course, themoving direction of the foaming agent may be changed later.

It is preferable that the filling direction of the second injection holeB4 is the same as that of the side frame 400. However, although thefirst injection hole B5 is located at the direct upper portion or directlower portion of the side frame 300, it is preferable that the secondinjection hole B4 is located at the position inclined to one side fromthe direct upper portion or direct lower portion of the side frame 400.

That is, the foaming agent injected through the second injection hole B4does not first move to the side frame 400 and flows along the lowerframe 600 located to be orthogonal to the side frame 400 and finallymoves along a length direction of the side frame 400.

In this case, a difference between the first injection hole and thesecond injection hole may be caused by a sectional difference of thefoaming spaces of the side frames 300 and 400. That is, the injectionhole is preferably provided at the direct upper portion or the directlower portion of the length direction of the side frame 300 having agreater section, and the injection hole is preferably provided at oneside (inclined toward the center of the door) inclined from the directupper portion of the direct lower portion of the length direction of theside frame 400 having a smaller section.

Of course, as described above, an injection pressure at the firstinjection hole B5 becomes greater, and more portion of the foaming spaceis filled with the foaming agent substantially injected through thefirst injection hole B5. For example, the foaming agent injected to thefirst injection hole B5 may be 70%, and the foaming agent injected tothe second injection hole B4 may be 30%.

Meanwhile, the rear frame 200 is preferably provided with vent holes 250formed to discharge the air remaining at the inner side of the sub door7 during injection of the foaming agent. The vent holes 250 may beformed at a gasket mounting groove 235 formed for mounting of the gasket40 along the rear frame 200.

The gasket mounting groove 235 may be formed to be recessed along thecircumference of the rear frame 200, and the vent holes 250 may beformed on the gasket mounting groove 592 at certain intervals. After thefoaming agent is fully filled, a sub door gasket 591 is mounted on thegasket mounting groove 235. Therefore, the vent holes 250 may be coveredby the sub door gasket 591 and is not exposed to the outside.

Meanwhile, the vent holes 250 may be formed at some area of the gasketmounting groove 235. The vent holes 250 may be formed at certainintervals along areas A and B where the upper frame 500 and the sideframe 400 are arranged as shown in FIG. 8. Particularly, the vent holes250 may be formed at certain intervals based on a corner where the upperframe 500 and the side frame 400 come across each other. Therefore, theair inside the sub door 50 may be discharged from an area adjacent tothe point where the foaming agent injected to the first injection holeB5 and the foaming agent injected to the second injection hole B4 comeacross each other, and the air continues to be discharged out until thefoaming agent is fully filled.

In other words, it is preferable that the vent holes 250 are formed atthe corner portion of the side frame 400 and the upper frame 500 in adiagonal direction of the first injection hole B4 having the greaterfoaming pressure.

Meanwhile, the lower frame 600 may be provided with a hinge mountingportion 610. Therefore, the second injection hole B4 is provided to bemore inclined toward the center portion of the door than the hingemounting portion 610. That is, it is preferable that a foaming sectionalarea of the side frame 400 corresponding to the hinge mounting portion610 is smaller than a foaming sectional area of the side frame 30 at theopposite position.

Also, the lower frame 600 may be provided with a sensor mounting portion620. A sensor for sensing approach of a human body or a sensor forsensing a touch input of a user or knock input to the panel assembly 10may be mounted on the sensor mounting portion 620. Therefore, it ispreferable that the first injection hole B5 is provided to be moreinclined toward the side of the door than the sensor mounting portion620.

That is, when foaming is performed after the door is arranged reversely,the foaming agent injected through the first injection hole B5 mayinitially move to the lower portion vertically (while the side frame 300is filled with the foaming agent) and then move to the second injectionhole B4 horizontally. The foaming agent injected through the secondinjection hole B4 may initially move to the first injection hole B5 andthen move to the lower portion vertically (while the side frame 400 isfilled with the foaming agent).

The injection cover which blocks the foaming injection holes throughwhich the foaming agent is completely injected may be coupled with thelower frame. Therefore, the foaming injection holes are blocked at theoutside of the door. Of course, the vent holes may be blocked. As aresult, thermal insulation performance of the door can be obtained andat the same time esthetic appearance can be provided.

The present invention is not limited to the aforementioned embodiments,and modifications can be made in the present invention by the personwith ordinary skill in the art to which the present invention pertains,within the scope of the present invention.

INDUSTRIAL APPLICABILITY

Industrial applicability is disclosed in the detailed description of thepresent invention.

It will be understood that when an element or layer is referred to asbeing “on” another element or layer, the element or layer can bedirectly on another element or layer or intervening elements or layers.In contrast, when an element is referred to as being “directly on”another element or layer, there are no intervening elements or layerspresent. As used herein, the term “and/or” includes any and allcombinations of one or more of the associated listed items.

It will be understood that, although the terms first, second, third,etc., may be used herein to describe various elements, components,regions, layers and/or sections, these elements, components, regions,layers and/or sections should not be limited by these terms. These termsare only used to distinguish one element, component, region, layer orsection from another region, layer or section. Thus, a first element,component, region, layer or section could be termed a second element,component, region, layer or section without departing from the teachingsof the present invention.

Spatially relative terms, such as “lower”, “upper” and the like, may beused herein for ease of description to describe the relationship of oneelement or feature to another element(s) or feature(s) as illustrated inthe figures. It will be understood that the spatially relative terms areintended to encompass different orientations of the device in use oroperation, in addition to the orientation depicted in the figures. Forexample, if the device in the figures is turned over, elements describedas “lower” relative to other elements or features would then be oriented“upper” relative to the other elements or features. Thus, the exemplaryterm “lower” can encompass both an orientation of above and below. Thedevice may be otherwise oriented (rotated 90 degrees or at otherorientations) and the spatially relative descriptors used hereininterpreted accordingly.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” when used in this specification, specify thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof.

Embodiments of the disclosure are described herein with reference tocross-section illustrations that are schematic illustrations ofidealized embodiments (and intermediate structures) of the disclosure.As such, variations from the shapes of the illustrations as a result,for example, of manufacturing techniques and/or tolerances, are to beexpected. Thus, embodiments of the disclosure should not be construed aslimited to the particular shapes of regions illustrated herein but areto include deviations in shapes that result, for example, frommanufacturing.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this invention belongs. It will befurther understood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art andwill not be interpreted in an idealized or overly formal sense unlessexpressly so defined herein.

Any reference in this specification to “one embodiment,” “anembodiment,” “example embodiment,” etc., means that a particularfeature, structure, or characteristic described in connection with theembodiment is included in at least one embodiment of the invention. Theappearances of such phrases in various places in the specification arenot necessarily all referring to the same embodiment. Further, when aparticular feature, structure, or characteristic is described inconnection with any embodiment, it is submitted that it is within thepurview of one skilled in the art to effect such feature, structure, orcharacteristic in connection with other ones of the embodiments.

Although embodiments have been described with reference to a number ofillustrative embodiments thereof, it should be understood that numerousother modifications and embodiments can be devised by those skilled inthe art that will fall within the spirit and scope of the principles ofthis disclosure. More particularly, various variations and modificationsare possible in the component parts and/or arrangements of the subjectcombination arrangement within the scope of the disclosure, the drawingsand the appended claims. In addition to variations and modifications inthe component parts and/or arrangements, alternative uses will also beapparent to those skilled in the art.

What is claimed is:
 1. A refrigerator comprising: a cabinet having astorage chamber; and a door configured to be rotatable with respect tothe cabinet; wherein the door comprises: a frame configured to define aspace into which a foaming agent is to be provided, the frame having atleast a first surface and a second surface, a first injection holeconfigured to inject the foaming agent into the space and disposed onthe first surface of the frame, a second injection hole configured toinject the foaming agent into the space and spaced apart from the firstinjection hole on the first surface of the frame, a gasket on the secondsurface of the frame, and vent holes provided on the second surface ofthe frame and spaced apart from the first and second injection holes,wherein the first surface of the frame is provided at an upper portionor a lower portion of the frame, and the second surface of the frame isprovided at a rear portion of the frame.
 2. The refrigerator of claim 1,wherein the frame includes an upper frame, a lower frame, a first sideframe, a second side frame, and a rear frame, wherein the lower frameincludes the first surface of the frame.
 3. The refrigerator of claim 2,wherein the space includes a first foaming path formed by the first sideframe and a second foaming path formed by the second side frame, whereinthe first foaming path extends in a vertical direction, and the secondfoaming path extends in the vertical direction.
 4. The refrigerator ofclaim 3, wherein at least a portion of the first injection hole isoverlapped with the first foaming path.
 5. The refrigerator of claim 2,wherein the rear frame includes a gasket mounting groove on which thegasket is disposed, and wherein the vent holes are disposed on thegasket mounting groove.
 6. The refrigerator of claim 1, wherein theframe includes a handle, and wherein the first injection hole is closerto the handle than the second injection hole.
 7. The refrigerator ofclaim 1, wherein the frame includes a hinge mounting portion, andwherein the second injection hole is closer to the hinge mountingportion than the first injection hole.
 8. The refrigerator of claim 7,wherein a distance between the second injection hole and the hingemounting portion is less than a distance between a center portion of thefirst surface of the frame and the first injection hole.
 9. Therefrigerator of claim 1, wherein the first injection hole is disposedopposite the second injection hole with respect to a center portion ofthe first surface of the frame.
 10. A refrigerator comprising: a cabinethaving a storage chamber; a main door configured to open and close thestorage chamber; and a sub door rotatably coupled to the main door;wherein the sub door comprises: a frame configured to define a spaceinto which a foaming agent is to be provided, the frame having at leasta first surface and a second surface, and the frame including anopening, a panel assembly to be in contact with the frame, wherein thepanel assembly comprises: a front panel made of a transparent material;and an insulation panel spaced apart from the front panel and thatcovers the opening; wherein the frame comprises: a first injection holeconfigured to inject the foaming agent into the space and disposed onthe first surface of the frame, a second injection hole configured toinject the foaming agent into the space and spaced apart from the firstinjection hole on the first surface of the frame, a gasket disposed onthe second surface of the frame, vent holes provided on the secondsurface of the frame and spaced apart from the first and secondinjection holes, wherein the first surface of the frame is provided atan upper portion or a lower portion of the frame, and the second surfaceof the frame is provided at a rear portion of the frame.
 11. Therefrigerator of claim 10, wherein the frame includes an upper frame, alower frame, a first side frame, a second side frame, and a rear frame,wherein the lower frame includes the first surface of the frame.
 12. Therefrigerator of claim 11, wherein the space includes a first foamingpath formed by the first side frame and a second foaming path formed bythe second side frame, and wherein the first foaming path is to extendin a vertical direction, and the second foaming path is to extend in thevertical direction.
 13. The refrigerator of claim 12, wherein at least aportion of the first injection hole is overlapped with the first foamingpath.
 14. The refrigerator of claim 11, wherein the rear frame includesa gasket mounting groove on which the gasket is disposed, and whereinthe vent holes are disposed on the gasket mounting groove.
 15. Therefrigerator of claim 11, wherein the lower frame includes a hingemounting portion, and wherein the second injection hole is closer to thehinge mounting portion than the first injection hole.
 16. Therefrigerator of claim 15, wherein the second injection hole is providedbetween the hinge mounting portion and a center portion of the firstsurface.
 17. The refrigerator of claim 10, wherein the frame includes ahandle, and wherein the first injection hole is closer to the handlethan the second injection hole.
 18. The refrigerator of claim 10,wherein the first injection hole is disposed opposite the secondinjection hole with respect to a center portion of the first surface.19. A refrigerator comprising: a cabinet having a storage chamber; and adoor configured to be rotatable with respect to the cabinet; wherein thedoor comprises: a frame configured to provide a space into which afoaming agent is to be provided, the frame including an upper frame, alower frame, a first side frame, a second side frame, and a rear frame,a first hole disposed on one of the upper frame or the lower frame, andconfigured to guide the foaming agent into the space, a second holedisposed on the one of the upper frame or the lower frame, andconfigured to guide the foaming agent into the space, the second holebeing spaced away from the first hole, a gasket on the rear frame of theframe, and a plurality of vent holes disposed on the rear frame of theframe.
 20. The refrigerator of claim 19, comprising a gasket mountinggroove on which the gasket is disposed, and wherein the vent holes aredisposed on the gasket mounting groove.